Formation of hydrogen bonding network of methane sulfonic acid at low degree of hydration (MSA)·(HO) (m = 1-2 and n = 1-5).

This study employs ab initio calculations based on density functional theory (DFT) to investigate the structural properties, H-NMR spectra, and vibrational spectra of methane sulfonic acid (MSA) at low degree of hydration. The findings reveal that energetically stable structures are formed by small clusters consisting of one or two MSA molecules (m = 1 and 2) and one or two water molecules in (MSA)·(HO) (m = 1-2 and n = 1-5).These stable structures arise from the formation of strong cyclic hydrogen bonds between the proton of the hydroxyl (OH) group in MSA and the water molecules.

The Role of Polymer Chain Stiffness and Guest Nanoparticle Loading in Improving the Glass Transition Temperature of Polymer Nanocomposites.

The impact of polymer chain stiffness characterized by the bending modulus () on the glass transition temperature () of pure polymer systems, as well as polymer nanocomposites (PNCs), is investigated using molecular dynamics simulations. At small values, the pure polymer system and respective PNCs are in an amorphous state, whereas at large values, both systems are in a semicrystalline state with a glass transition at low temperature. For the pure polymer system, initially increases with and does not change obviously at large .

Physicochemical Properties of Organic Molecular Ferroelectric Diisopropylammonium Chloride Thin Films.

We fabricated ferroelectric films of the organic molecular diisopropylammonium chloride (DIPAC) using the dip-coating technique and characterized their properties using various methods. Fourier-transform infrared, scanning electron microscopy, and X-ray diffraction analysis revealed the structural features of the films. We also performed ab-initio calculations to investigate the electronic and polar properties of the DIPAC crystal, which were found to be consistent with the experimental results.

Surface Atomic Arrangement of Aluminum Ultra-Thin Layers Grown on Si(111).

Surface atomic arrangement and physical properties of aluminum ultrathin layers on c-Si(111)-7 × 7 and hydrogen-terminated c-Si(111)-1 × 1 surfaces deposited using molecular beam epitaxy were investigated. X-ray photoelectron spectroscopy spectra were collected in two configurations (take-off angle of 0° and 45°) to precisely determine the surface species. Moreover, 3D atomic force microscopy (AFM) images of the air-exposed samples were acquired to investigate the clustering formations in film structure.

First-Principles Prediction of New 2D -SiPN: A Wide Bandgap Semiconductor.

Pentagonal two-dimensional ternary sheets are an emerging class of materials because of their novel characteristic and wide range of applications. In this work, we use first-principles density functional theory (DFT) calculations to identify a new pentagonal SiPN, -SiPN, which is geometrically, thermodynamically, dynamically, and mechanically stable, and has promising experimental potential. The new -SiPN shows an indirect bandgap semiconducting behavior that is highly tunable with applied equ-biaxial strain.